Multicolor sheet fed printing machine



July 14, 1964 w. KOCH 3,140,657

MULTICOLOR SHEET FED PRINTING MACHINE Filed Jan. 24, 1962 2 Sheets-Sheet 1 n n jg N E W HMNWIHW a Jnvenfor;

firroR Meys July 14, 1964 w. KOCH MULTICOLOR SHEET FED PRINTING MACHINE 2 Sheets-Sheet 2 Filed Jan. 24', 1962 Jnvenfor: /ERNER Koo; a Ne W flT'T'QR/Vfi/J United States Patent MULTICOLOR SHEET FED PRINTING MACHINE Werner Koch, Offenbach am Main, Germany, assignor to Roland Gifsetmaschinenfabrik Faber & Schleicher AG.,

Ofienbach am Main, fiermany, a German body corporate Filed Jan. 24, 1962, Ser. No. 168,431 Claims priority, application Germany Feb. 4, 1961 9 Claims. (Cl. 101-183) This invention relates to multicolor printing machines and it particularly relates to a machine of that class consisting of at least two printing units which are positioned one behind the other in their sheet feeding direction and in which the sheets are taken over from the first unit and transferred to the second unit by a chain conveyer of variable length driven by both units simultaneously.

It is known in machines of that type to change the working length of the chain conveyer by enabling the lower strand of the conveyer to take a variable sag, whereby a feeler device is provided to influence the speed regulation of the two units so that the amount of the sag in the slack strand will be maintained at a predetermined value. When a test sheet is taken from the first unit, the amount of sag is reduced. The feeler device then responds, and the two units will operate at different speeds until the amount of sag has resumed its previous value.

If several successive sheets are left out as will be the case, for instance, when the machine runs out, the feeler device gives a permanent signal, but the slack strand would nevertheless stretch an inadmissible amount. In one of its more important aspects the invention particularly aims at removing this disadvantage as for instance by the provision of means, such as a clutch, intermediate the two printing units and preferably at that place at which the chain conveyer is connected to the first unit, by which the drive of the conveyer by this first unit may be interrupted, while the second unit continues its drive. This makes it possible to change the amount of sag also independently at the respective differences in the speed of the two machines.

The invention, further, consists in the provision of control means which permits control of the operation of the machine when test sheets are removed at a place intermediate the first unit and the chain conveyer in accordance with the number of sheets removed. This provides to determine positively and in advance all sheets which will be left out and thereby would influence the operation of the intermediate conveyer.

In connection therewith the invention further provides that the control means will not respond in the case of the selective removal of a number of sheets successively. Preferably this is effected by an impulse which is given each time when a sheet is being removed, which impulses are accumulated by mechanical, electrical, or other means so that, within a selective number of successively removed sheets, a clutch becomes disengaged whereas, if the selected number of successively removed sheets is exceeded by one, the accumulation becomes nullified, so that the clutch remains closed, and both units will continue to run at their respective speeds. This enables the number of possibly left out sheets to be suited to the accumulating capacity of the intermediate conveyer, and the interruption of the drive between the first unit and the conveyer to take place only when, within practical limits, the selected number of left out sheets will not be exceeded.

A preferred embodiment of the above indicated invention comprises a control arrangement, essentially consisting of a plurality of mutually parallel cylindrical slides, or bolts, arranged in halves which, hereinafter, will be referred to as double bolts, or control bolts. These control bolts are equidistant from each other and individually Patented July 14, 1964 "ice.

displaceable in axial direction within predefined limits. In the cycles of operation they are advanced step by step, whereby a feeler device responding to left out sheets actuates a double switch which, in turn, serves to displace each two cooperating halves of the control bolts into an end position, in which one set of halves effects the disengagement of the clutch, while the other permits of counting the successively removed sheets. These control bolts may be fitted either to their respective chain conveyer system or, separate therefrom, in a special drum or cylinder which is synchronously rotated by the machine in such a manner as to be advanced by one step in every cycle of operation of the machine.

For the purpose of counting the successively removed sheets the invention, for example, provides a pivoted lever adapted to swing in a plane which is vertical to the axes of the control bolts and which, each time when it encounters a sheet, is oscillated by these bolts out of their travelling path. But if a selected number of succeeding sheets are missing, this lever swings into the paths of the bolts and thereby initiates the pushing back of the clutch disengaging bolt-halves, which had previously been displaced by the double switch, before the bolt halves would give the sign for the disengagement of the clutch.

The arrangement of the control bolts which, so to say, are able to receive an order which is taken over at differentiating times, constitutes a simple, sturdy and safe construction; It also permits in a most simple manner to vary the number of successively to be removed sheets.

For the return of the clutch disengaging bolt halves the invention provides a displaceable switch which, when moving into its working position, pushes all bolt halves back into their operating region. This double switch is slanted at its ends so that in its operative position it positively returns all arriving bolt halves into their inoperative positions.

The accompanying drawings diagrammatically illustrate an embodiment of the invention by way of example. In these drawings,

FIG. 1 is a side view of a two unit multicolor printing machine,

FIG. 2 is an end view of the controlling device,

FIG. 3 is a detail,

FIG. 4 shows a developed plan view of FIG. 2,

FIG. 5 a fragmentary side view, partly in section, of FIG. 4.

FIG. 6 is a diagrammatic sectional view of the clutch of the machine and a diagram of the circuitry for control of the coupling, and

FIG. 7 is a fragmentary view of an electrical control element of the clutch.

The multicolor sheet printing machine illustrated consists of two printing units 1 and 2 which are operatively connected to one another by a chain conveyer 3 adapted to receive the printed sheets from the first unit 1 and to transfer them to the second unit 2. The sheets are taken up in known manner from the pile 5 of the feeding device 4 and advanced over the feed table 6 into the unit 1 to be eventually taken olf by the stacking device 7 at the end of the printing unit 2 and deposited on the stack 8 thereof.

The sheets 9, over part of their track, are freely suspended from the lower strand of the chain conveyer 3, the speed of which is preferably lower than the printing speed of the printing units 1 and 2. The chain conveyer is driven by a sprocket wheel 10 at the unit 1 and by another sprocket wheel 11 at the unit 2. The sprocket 11 always runs synchronously with the unit 2, whereas in the driving arrangement of the sprocket 10 a clutch is interposed which is preferably encased in a housing 12. The sprocket 10 is driven by a bevel gear 13 over the shafts 14, 15 and another bevel gear in the casing 16.

Both sprockets 10 and 11 are provided in duplicate, one at each side of the machine.

If a sheet is taken out in the unit 1, then the clutch 12 becomes disengaged for the duration of a full machine cycle, so that the chain conveyer 3 will be driven by the sprockets 11 only. Hereby the lower strand of the conveyer 3 becomes shorter until it takes the position 17 shown in broken line in FIG. 1, whereby the lengthening of the upper strand between the sprockets 10 and 11 is taken up by the resiliently arranged sprocket 18. A resilient mounting of sprocket 18 may be effected in any suitable and conventional manner. The sprocket is shown as being supported on the free end of a lever 101 which is pivotally seated 011 a shaft for a chain wheel 102. A compression spring 103 which on one end abuts against an abutment member 104 on the frame of machine 1 seeks to turn lever 101 in counterclockwise direction thus permitting resilient displacement of sprocket 18 by the pull of conveyer 3. The controlling device which is shown in FIG. 2 comprises a drum or cylinder 19 which is driven from the unit 1 synchronously in a known manner, such as is disclosed in US Patent 2,714,351 to Koch, such that the bolts 20, 21 which are located around its circumference are advanced by the amount of the distance between two of these bolts, said distance conforming to the pitch of the bolts on the face end of the cylinder as indicated in FIG. 2.

Each of the bolts 20, 21 is provided with an outwardly extending pin 22 (FIG. bearing a turnable roller 23 at its free end and extending through a slot 24 in the mantle of the cylinder 19. A stationary double switch 25 is provided to push all bolts as they arrive back into their initial position, in which the bolts 20 are retracted, while the bolts 21 project to the outside. A feeler (not shown) which responds to the empty places of removed sheets in unit 1 energizes a magnet 26 whenever a sheet is missing, whereby the double switch 27 enters into the path of the rollers 23 so that the bolts 20, 21 are pushed into their other end positions. Hereby the double switch 27 turns on its pivot 28 on the bearing 29 and is withdrawn by a spring 30 into its inoperative position against a stop 31, while an abutment 32 is provided to limit the working position when the magnet, or solenoid, 26 becomes energized. A feeler 33 extends into the path of the ends of bolts 20. This feeler is lifted by each of the advancing bolts 20 against the action of a spring 34 and thereby closes an electric switch 35 which, in turn, ef fects the disengagement of the clutch 12, whereby a stop 36 serves to determine the inoperative position of the feeler 33. Every contact of the switch 35 which is established by one of the projecting bolts 20 causes the disengagement of the clutch 12 for the duration of a working cycle of the machine.

Clutch 12 which is diagrammatically shown in FIG. 1 should be visualized as being a suitable and conventional clutch controlled by switch 35 in a conventional manner. FIGS. 6 and 7 show such clutch. A clutch disk 201 is keyed to the respective end of shaft 15. An exciter winding 202 is fitted in a peripheral groove of the disk. The winding may be energized by means of slip rings 203 insulated from the body of disk 201 and brushes 204. A second clutch disk 205 is seated upon shaft 14 secured against rotation, but lengthwise displaceable. An exciter winding 208 of the second disk is supplied with current by means of insulated slip rings 206 and brushes 207. Springs 209 urge disk 205 towards the right, that is away from disk 201. As it is evident, energization of windings 202 and 208 will cause attraction of disk 205 toward disk 201 whereby claws 210 provided on the sides of the disks facing each other become engaged. As a result rotation of shaft 14 will be transmitted to shaft 15.

Energization of windings 202 and 208 is controlled by switch 35. The switch connects the windings to a D.-C. source of current through a rotary switch 212, brushes 213 and 214, and a polarized relay 211. FIG. 7 shows in detail the coaction of brushes 213 and 214 with the contact strip of rotary switch 212. The clutch, switch 35 and relay 211 are shown in the position in which the energizing circuit for windings 202 and 208 is disconnected.

There is another feeler 38 turnable on a pivot 37 which is urged by a spring 39 into contact with an abutment 40, thereby closing an electric switch 42 by a projecting arm 41 of the feeler 38. As will be seen from FIGS. 2 and 4, this feeler can turn in counter-clockwise direction only when a definite number of bolts 21 has been pushed back into the cylinder 19 by the operation of the switch element 27. These bolts, in FIG. 2, are the three bolts denominated 55. If less than three bolts are pushed in, then the feeler 38 will be lifted and the electric switch 42 opened. Closing the switch 42 will energize the solenoid 43, so that its armature 44 moves to the left as shown in FIG. 5 and causes the toggle 45 to assume its stretched position and to thereby move the bridge 46 in the direction of the cylinder 19. This causes the return of all bolts 20 within the region of the bridge 46 which had previously been displaced by the mechanical switch 27 before they were able to contact with and lift the cam 47 of lever 33.

The bridge 46 is provided with slanted side panels 48 which ensure that all approaching bolts 20 will be pushed back into their initial positions. It is slideably journaled in a bearing 50 by means of two bars 49 and, when the solenoid 43 is Without current, is urged by a spring 51 over the armature 44 and the toggle 45 into its position of rest. The bolts 20, 21 are secured in their extreme end positions by a catch 52.

If only one sheet is signalled to be missing, then only one pair of bolts 20, 21 will be displaced, of which the bolt 20 will lift the lever 33 by contacting its cam 47. This closes the switch 35 and disengages the clutch 12 for the duration of one complete cycle of operation of unit 1. If two sheets have been removed then the switch 35 will be closed twice and the clutch kept open for the duration of two working cycles. But when three or more sheets have been removed, then lever 38 falls in, the bridge 46 is moved into action and pushes the bolts 20 back before they are able to engage the cam 47. In this case the signals, which have been held over by the action of the bolts 20, will be nullified, clutch 12 remains closed, and the chain conveyer 3 will continue to travel with its ordinary amount of sag. If the clutch is to remain closed already with two or more sheets missing, then the eifective contact surface of the lever 38, which is in engagement with the bolts 20, must be shortened from point 53 to point 54 by the amount of one pitch, so that lever 38 will be able to turn in counter-clockwise direction already when two of the bolts 21 are pushed back.

When three or more sheets are taken out of the machine and as a result clutch 12 remains closed, both machines 1 and 2 and conveyer 3 continue to operate until the second machine 2 for the first time does not receive a sheet. As previously indicated, both machines are equipped in a well known and conventional manner with detectors which trip the respective machine. When no sheet is fed to the same, the second machine is now also tripped. In the event the conveyer chain is reduced to the limits of its capacity by the repeated removal of sheets, which reduction is apparent from the position of the resiliently mounted sprocket 18, the entire machine is stopped. It is conventional to provide a signal means which is controlled by the position of sprocket 18 and gives the operator of the machine advance warning that no further sheets should be taken from the machine until the supply of sheets is replenished.

What I claim is:

1. In a printing machine having at least two successively arranged printing units, a chain conveyer intermediate the two printing units carrying sheets therebetween, drive means for driving said chain conveyer simultaneously from both units, means for varying the working length of said chain conveyer, and control means associated with one of said printing units, for interrupting the drive means of the conveyer chain at said one printing unit for a predetermined number of working cycles of said printing unit as determined by a change in the number of sheets carried by said conveyer, while continuing the drive of said chain at the other unit.

2. In a printing machine having at least two successively arranged printing units, a chain conveyer intermediate the two printing units carrying sheets therebetween, drive means for driving said chain conveyer simultaneously from both units, means for varying the working length of said chain conveyer, a clutch associated with one of said printing units and operatively engageable with the drive means of said chain conveyer at said one printing unit, and means responsive to a change in the number of sheets carried by said conveyer for disconnecting said clutch from the drive means of the chain conveyer at said one printing unit while the drive means of said chain conveyer at the other printing unit is being continued.

3. A printing machine consisting of at least two printing units arranged successively in their direction of feed, a sheet-carrying chain conveyer operatively connecting the two printing units, drive means in association with each of said printing units for simultaneously driving said chain conveyer from both units, means for varying the working length of said chain conveyer, a clutch on the first-in-succession printing unit, means intermediate said clutch and the drive means for said chain conveyer at said first printing unit for engaging and disengaging said clutch for the purpose of interrupting the drive means of said chain conveyer at said first printing unit a determined number of working cycles as determined by a change in the number of sheets carried by said conveyor, while the drive of the second printing unit is being continued.

4. A multicolor printing machine consisting of at least two successively arranged printing units, a sheet-carrying chain conveyer operatively connecting the two printing units, means associated with each of said printing units for simultaneously driving said chain conveyer from both units, means for varying the working length of said chain conveyer, comprising, a clutch on the first-in-succession printing unit, means intermediate said clutch and the drive means for said chain conveyer at said first printing unit for engaging and disengaging said clutch, and control means for said clutch which become active at the removal of sheets from said conveyer chain at a place intermediate the first printing unit and said conveyer chain so that said clutch becomes disengaged for as many working cycles as sheets have been removed.

5. In a multicolor printing machine as set forth in claim 4, wherein said control means comprises means for preventing the clutch from being disengaged when a successive but variable number of sheets are removed from said conveyer.

6. A multi-color printing machine consisting of at least two successively arranged printing units, a sheet-carrying chain conveyer operatively connecting the two printing units, drive means associated with each of said printing units for simultaneously driving said chain conveyer from both units, means for varying the working length of said chain conveyer, a clutch on the first-in-succession printing unit, operative means intermediate said clutch and the drive means for said chain conveyer at said first printing unit for engaging and disengaging said clutch, clutchdisengaging means for the said clutch adapted to become active when encountering an empty space due to the removal of a sheet from said conveyer chain, other means for preventing the action of said clutch-disengaging means when a variable number of empty spaces are encountered on said conveyer chain, and signal means for producing and storing a signal at each removal of a sheet from said conveyer such that in the event of a predetermined number of sheets being successively removed, the clutch becomes disengaged, while in the event of said number being exceeded by one, said stored-up signals will become etfaced and the clutch will remain closed.

7. A multicolor printing machine as set forth in claim 6, wherein said clutch-disengaging means, said other means, and said signal means comprise a plurality of equidistantly pitch control bolts, a cylinder in which said control bolts are slidable so as to be capable of limited axial displacement, means for advancing said bolts in said cylinder in the sequence of sheet delivery by one pitch at a time, a feeler device adapted to respond to an empty space in said chain conveyer for displacing said control bolts from one of their end positions into the other, and means for controlling said feeler device for moving a double switch so that one end of said bolts disengages said clutch while the other end permits counting the successively removed sheets.

8. A multicolor printing machine as set forth in claim 6, wherein said clutch-disengaging means, said other means, and said signal means comprise equidistantly pitched bipartite control bolts of which the parts at one end of said bolts are adapted to disengage the clutch while the other parts at the opposite ends of said bolts permit counting the successively removed sheets, further com prising means movable at right angles to said bipartite bolts and adapted to be swung out of the path of said bolts when sheets are present on said conveyer, but to be swung into the path of said bolts when a predetermined number of successive sheets has been removed from said conveyer.

9. In a multicolor printing machine as set forth in claim 6, wherein said clutch-disengaging means, said other means, and said signal means further comprise a displaceable mechanical switch for the return of the bolts which have caused the disengagement of the clutch, said mechanical switch having slanted arms adapted, when said mechanical switch is in its working position, to return all previously displaced bolts into their inoperative positions.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A PRINTING MACHINE HAVING AT LEAST TWO SUCCESSIVELY ARRANGED PRINTING UNITS, A CHAIN CONVEYER INTERMEDIATE THE TWO PRINTING UNITS CARRYING SHEETS THEREBETWEEN, DRIVE MEANS FOR DRIVING SAID CHAIN CONVEYER SIMULTANEOUSLY FROM BOTH UNITS, MEANS FOR VARYING THE WORKING LENGTH OF SAID CHAIN CONVEYER, AND CONTROL MEANS ASSOCIATED WITH ONE OF SAID PRINTING UNITS, FOR INTERRUPTING THE DRIVE MEANS OF THE CONVEYER CHAIN AT SAID ONE PRINTING UNIT FOR A PREDETERMINED NUMBER OF WORKING CYCLES OF SAID PRINTING UNIT AS DETERMINED BY A CHANGE IN THE NUMBER OF SHEETS CARRIED BY SAID CONVEYER, WHILE CONTINUING THE DRIVE OF SAID CHAIN AT THE OTHER UNIT. 